1. Field of the Invention
The invention relates to a process for preparing amino-functional cyclodextrin derivatives having an amino function which is linked to the cyclodextrin (CD) via a spacer.
2. The Prior Art
The following processes for preparing cyclodextrin derivatives in which the amino function is linked to the cyclodextrin via a spacer are known from the literature:
CA 117:92570 (corresponds to JP 04100801) discloses the preparation of 2-dialkylaminoethyl-substituted CD's by alkylating CD using dialkylaminoethyl chloride. Only tertiary amines can be produced by this process since, otherwise, the problem arises of the formation of polyethyleneimine chains. Furthermore, in this process, the corresponding salt is formed in stoichiometric quantities as a waste product, in turn necessitating an elaborate separation of the substituted CD's.
U.S. Pat. No. 3,553,191 discloses the reaction of CD with ethyleneimine in the presence of acetic acid to form 2-aminoethyl-substituted CD's. The problem of the formation of polyethyleneimine chains also arises in this process. A further disadvantage of this process lies in the use of ethyleneimine, which is known to be very toxic and carcinogenic.
DE-A-41 36 325 discloses a number of amino-functional CD derivatives. As regards their preparation, reference is made to a number of publications in the literature.